Transmission



Reissued Aug. 9, 1927.

UNITED STATES PATENT oFFicE.

SIDNEY W. FARNHAM, OF CHICAGO, ILLINOIS, ASSIGNOR TO GOODMAN MANUFACTUR-ING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LOCOMOTIVE.

Original No. 1,558,971, dated October 27, 1925, Serial No. 758,023, ledDecember 26, 1924. Application for reissue led April 6, 1927, Serial No.181,578.

This invention relates to improvements in mine locomotives and moreparticularly to combined trolley and gathering locomotives in which thelocomotive may be operated selectively by power obtained thro-ugh one ormore trolleys or through gathering reel of the usual type having aconductor cable wound thereon and adapted to be detachably connected tothe power lines in a main transportation entry while the. locomotive isbeing operated over unwired tracks as for instance branch tracksextending into remote portions of a mine.

The purpose of this invention is to provide means for preventingsparking between the locomotive wheels and the rail while the power isbeing supplied through the cable reel so that the locomotive can besafely operated with the reel connections in remote portions of the minewherel explosive gas is likely to accumulate and form a potent source ofdanger from sparks ordinarily caused by the returning current from thepower line passing through the locomotive wheels and from them to themine tracks.

My invention may be best understood by reference to the accompanyingdrawings in which:

Figure 1 is a diagrammatic view illustrating one embodiment of myinvention as applied to an electric locomotive.

In these drawings, l() indicates a main power supply line such as atrolley wire and 11 indicates a track forming a power return. It isunderstood that the trolley and track extend along main transportationlines which are usually well ventilated so as to eliminate any danger ofexplosions such as might be caused by the operation of an electricmotor.

The remaining portions of the diagrams indicate parts mounted upon anelectric locomotive of the combined trolley and gathering reel type.

In the form shown the locomotive is provided with two trolley poles 12and 13, and a gathering reel 14 having a cable 15 of the duplex typeincluding two leads 16 and 17. These leads are provided with suitableterminal devices of the usual character for engagement respectively withthe trolley 10 and track 11. These devices need not be shown in detailas they are Well known and t'orm no part of the present invention. Thelocomotive is also provided with a pair ot' motors 20 and 21, having theusual field windings 22, 22, and armatures 23, 23. The motors arecontrolled by any suitable controlling device such as a control drum 21having resistances 26, 26, associated therewith in any suitable manner,and a reversing drum 2T suitably connected for reversing the directionof curi'ent through the motors. Details ot' these controlling devicesneed not be described for the purpose of the present invention exceptingto point out a main lead 28 leading to the control drum and a secondlead 29 leading to the field windings 221 22. These latter leads areadapted to complete the circuit from the source of supply.

In electric locomotives of this type adapted to receive power fromeither one ot' two trolley poles, such as the poles 12 and 13 and froman electric conductor or gathering reel such as the reel 14, :inindependent three-way switch is usually provided so as to render two ofthe supply sources dead or disconnected when the third is in operation.In the present invention I provide an additional switch or set ofcontacts in which the return connection of the motor circuit is made toa. ground upon the frame of the locomotive when operating from one orthe other of the trolleys and another connection, unconnected,electrically, with the locomotive frame, is made from the motor returncircuit to one side of the gathering reel and thence directly throughthe conductoi cable when operating through the reel. In the form shownthis switch is indicated generally at 35 and comprises a contactor arm36 pivotally connected at 37 to one of the main motor circuit leads 28.The upper end 38 of this switch is adapted to engage with a plurality ofcontacts T1, T1, or R. The lower end 39 of this switch member is adaptedto engage with contacts G1, G1, or R1, the arrangement being such thatthe circuit is completed either from T2 to G2, R to R1, or T1 to G1. Thetwo contacts G1 and G2 have a common connect-ion to the frame of theIocomotive. Thus it will be seen that when the switch is connected witheither of the trolleys 12 and 13 by engaging their respective contactsT1 or T2, as the case may be, the motor circuit is completed through therespective ground connections Gr1 or G2, to the locomotive frame atpoint 40. Thus while the locomotive is operating over the main trackswith either of the trolleys in engagement with the main supply line, theground connection is provided in the usual way through the locomotivetrame and track wheels to the track 11. On the other hand when it isdesired to supply current through the trolley reel, the switch member 36is rotated to connect with contacts R and R1, in which case the returnconnection from the lead 29 is connected to a conductor 41 havingengagement with a contactor ring 42 carried by the reel and connected toone of the cable conductors 17. The other motor lead 28 is connectedthrough a conductor 43 to a contacting ring 44 on the reel connectedwith the other cable conductor 16. Thus the motor circuit is whollydisconnected from the frame, and the possibility of arcing between thelocomotive wheels and the track is entirely eliminated when the power isbeing supplied through the cable reel. It is preferable in locomotivesof this character to enclose the operating parts of the locomotivewherein arcs arev likely to occur as well as the conductor rings on thegathering reel. Similarly the switching device is enclosed as forinstance indicated by the casing 45 shown in the diagram surrounding theswitching device 35.

From the above description it will be understood that the locomotive maybe operated in the usual manner with a ground return from the motorpassing through the locomotive frame and wheels and the return track,without danger of causing explosions since the main haulage entries areusually sutliciently ventilated to eliminate danger from explosivegases. However, when operating on the gathering reel in remote portionsof the mine where the Ventilating system is not so e'ective, my improvedswitching device automatically provides a return circuit through theduplex cable reel instead of through the locomotive ground on thelocomotive trame and the mine tracks and thus providing a safeguardagainst explosions in the more dangerous areas of the mine.

While I have shown and described one embodiment of my invention, it willbe understood that the construction and arrangement of the various partsmay be altered without departing from the spirit and scope thereof.Furthermore, I do not wish to be interpreted as limiting myself to theparticular construction illustrated, excepting as it may be specificallylimited in the appended claims.

I claim as my invention:

1. In a gathering locomotive provided with control and reverse drums,and with a motor circuit adapted to be selectively connected with a4source of power supply through a trolley or a gathering reel, a doubleconductor cable and rotating contactor devices associated with saidgathering reel, and switching means independent of said reverse drum forcompleting said motor circuit through the trolley and a groundconnection on the locomotive trame in one position, and completing thecircuit through the double conductor cable and contact devices on thegathering reel, when in a second position, said last named circuit beingwholly disconnected from said locomotive frame.

2. In a gathering locomotive provided with control and reverse drums,and with a motor circuit adapted to be selectively connected with asource of power supply through a trolley or a gathering reel, a doubleconductorl cable and rotating contactor devices associated with saidgathering reel, a set of contacts including one connected to the trolleyand another to a ground connection on the locomotive frame, a separateset of contacts electrically connected with said contactor devices andentirely unconnected with said locomotive frame, and switching meansseparate from said reverse drum for selectively completing said motorcircuit through either said first set of contacts or said secondmentioned set of, contacts, as desired.

Signed at Chicago, in the county of Cook and State of Illinois, this 4thday of April, A. D. 1927 SIDNEY W. FARNHAM.

